为了提高信息传输的保真度,研究了缺陷磁场对自旋系统中纠缠和保真度的作用,讨论了不同方向缺陷磁场、温度、各向异性作用对纠缠和量子通讯的影响. 研究发现,由z方向的磁场诱导的纠缠一般较x方向磁场诱导的纠缠大. z方向磁场和x方向磁场对保真度的影响具有竞争作用,反铁磁系统更适合于信息的传输. [关键词] 量子通讯,量子纠缠,保真度In order to enhance the fidelity in quantum communications,we investigate the effects of different defect magnetic field on the entanglement and information transmission in a quantum spin model. We discuss the effects of different defect magnetic field,temperature and anisotropy interaction on the entanglement and quantum communication. The results show that the entanglement in z-direction is stronger than x-direction. There is competition relation between the two different magnetic fields. We also find that the antiferromagnetic system is more proper for information transmission
